Electrical power loss while driving?

Tiny
RO83AA
  • MEMBER
  • 2001 TOYOTA AVALON
  • 2WD
  • AUTOMATIC
  • 112,000 MILES
A few times in the past 2 weeks the power from the radio turned 'off' for a second and then came back 'on'. This past Saturday we were driving, at night, home on the interstate. This time when the radio went out the whole car's power went out. There was no power to the whole car for 2 or 3 seconds. (No lights in the car, no headlights, it also felt like there was no engine power) I turned off the headlights switch to 'off' and then back to 'on' and then the power came back 'on' to the whole car. It seemed fine but I pulled over to the next Rest Area. I checked the radio fuss it was fine. I checked the battery terminals and tightened the nut on the positive terminal a little bit more. The 'Check Engine" warning light has not come on nor has it ever come on during these past 2 weeks. Does anyone have an explanation for what happened? What else should I check?
Sunday, August 20th, 2023 AT 9:41 PM

11 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,321 POSTS
This sounds like the battery has a bad connection or the battery is shorting out internally. Please go over these guides to help confirm the issue:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

and

https://www.2carpros.com/articles/car-battery-load-test

Please go over these guides and get back to us.

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Monday, August 21st, 2023 AT 1:38 PM
Tiny
RO83AA
  • MEMBER
  • 41 POSTS
I checked the battery terminals, and I didn't see corrosion. So, I did the load test. After 15 minutes I checked the voltage of the battery. It was at 12.03. I had someone start the car as I watched the headlights, and they did not dim that much. Then I checked the voltage again. It was reading 14.12. I checked our maintenance paperwork, and the battery was replaced on 12.11.2020.
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Monday, August 21st, 2023 AT 4:07 PM
Tiny
KEN L
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These readings are okay but if the battery is getting jostled around while driving it can short out, I would replace the battery still. Do you have a used battery you can swap in to help with the test?
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Tuesday, August 22nd, 2023 AT 10:50 AM
Tiny
RO83AA
  • MEMBER
  • 41 POSTS
No, I don't have another battery, but a friend might have one. How would having another battery help with the test? What would I do?
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Tuesday, August 22nd, 2023 AT 1:12 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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I would swap the battery out for another one to see if the problem stops.

This guide can help:

https://www.2carpros.com/articles/how-to-replace-a-car-battery

Please go over this guide and get back to us.
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Thursday, August 24th, 2023 AT 10:19 AM
Tiny
RO83AA
  • MEMBER
  • 41 POSTS
So, my son's car issue with on-and-off power loss is still happening. This past weekend, I was able to go up to my son's Uni and look at the car. Looking at the terminals and saw that the positive terminal is closing kind of crocked. So, it's not tight. I think I need to replace the terminal. Could you tell me how to figure out the gauge of the wire to the battery terminals?
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Wednesday, November 15th, 2023 AT 8:32 PM
Tiny
KEN L
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It will be 1 or 2 gauge wire, can you upload an image of the problem so I can walk you through how to fix it?

Please go over this guide as well:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Please go over this guide and get back to us.
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Thursday, November 16th, 2023 AT 10:20 AM
Tiny
RO83AA
  • MEMBER
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Here are images of the terminal. This is after both terminals were cleaned. The positive terminal won't tighten enough to keep the terminal from moving. When tightening the bolt (positive side) one side is closing crocked.
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Thursday, November 16th, 2023 AT 3:19 PM
Tiny
RO83AA
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  • 41 POSTS
Looks like there are 2 cables that are connected together.
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Thursday, November 16th, 2023 AT 3:38 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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Thanks for the images, you need a battery cable end and then remove the nut from your old cable end to transfer the cable over. Here is one on Amazon for $7.00:

https://amzn.to/49UMx4X

Let us know if you need anything else.
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Friday, November 17th, 2023 AT 11:07 AM

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